Journal article
Measuring Motion-Induced B0-Fluctuations in the Brain Using Field Probes : Motion-Induced B0-Fluctuations in the Brain
Center for Magnetic Resonance, Department of Electrical Engineering, Technical University of Denmark1
Department of Electrical Engineering, Technical University of Denmark2
Center for Hyperpolarization in Magnetic Resonance, Centers, Technical University of Denmark3
Department of Applied Mathematics and Computer Science, Technical University of Denmark4
Cognitive Systems, Department of Applied Mathematics and Computer Science, Technical University of Denmark5
Leiden University6
University Medical Centre Utrecht7
Leiden University Medical Center8
Purpose: Fluctuations of the background magnetic field (B0) due to body and breathing motion can lead to significant artifacts in brain imaging at ultrahigh field. Corrections based on real-time sensing using external field probes show great potential. This study evaluates different aspects of field interpolation from these probes into the brain which is implicit in such methods.
Measurements and simulations were performed to quantify how well B0-fluctuations in the brain due to body and breathing motion are reflected in external field probe measurements. Methods: Field probe measurements were compared with scanner acquired B0-maps from experiments with breathing and shoulder movements.
A realistic simulation of B0-fluctuations caused by breathing was performed, and used for testing different sets of field probe positions. Results: The B0-fluctuations were well reflected in the field probe measurements in the shoulder experiments, while the breathing experiments showed only moderate correspondence.
The simulations showed the importance of the probe positions, and that performing full 3rd order corrections based on 16 field probes is not recommended. Conclusion: Methods for quantitative assessment of the field interpolation problem were developed and demonstrated. Field corrections based on external field measurements show great potential, although potential pitfalls were identified.
Language: | English |
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Publisher: | Wiley |
Year: | 2016 |
Pages: | 2020-2030 |
ISSN: | 07403194 and 15222594 |
Types: | Journal article |
DOI: | 10.1002/mrm.25802 |
ORCIDs: | Hanson, Lars G. and Madsen, Kristoffer Hougaard |
Algorithms Artifacts Brain Brain Mapping Computer Simulation Humans Image Enhancement Image Processing, Computer-Assisted Magnetic Fields Magnetic Resonance Imaging Magnetic Resonance Spectroscopy Male Models, Statistical Phantoms, Imaging Respiration dynamic shimming field fluctuations field mapping motion